It is well known (e.g. section 9.4 of [1]})
that the Virasoro algebra acts by intertwining operators on any \(\widehat{sl}_{n+1}-moduleof positive energy. In this way a positive energy representation gives a representationof the Virasoro algebra.Irreducible representations are classified according to theircentral charge \) c\( and conformal dimension \) h\(.\) Representations of the Virasoro algebra can be used to construct special examples of conformal field theories called minimal models; in a minimal model, the Hilbert space of the theory is a sum of finitely many irreducible representations, and the representations which occur are highly restricted. The theory of these
“Virasoro minimal models” is described in [2]}.
